The threat of ingestion of large pieces of plastic that can be seen with the naked eye is something that is easy enough to understand. If you are eating something that isn’t food, it can cause internal damage, lead to starvation etc.
The threat of microplastic ingestion is a little bit less straight forward, but equally concerning. Microplastics are ubiquitous in the worlds oceans, estimates of more than 50 trillion pieces already clog our seas. Their entrance into the marine food web can start with plankton (check out this video of an arrow worm eating a microfiber), or any filter feeders (things like shell fish).
Do these micro plastics travel up the food chain?
It’s hard to tell, but scientists seem to think it could, which would be a significant threat to human health. The first step is to seeing that there are micro plastics in some of these bottom of the food web organisms. Next, the question is do these plastic particles move into the body. So far research has only reached as far as filter feeding bivalves, but there was found plastic particles in the soft tissue of muscles and oysters on the market for human consumption. This suggests that microplastics can be integrated into soft tissue, making it a prime candidate for bioaccumulation. It also tells us that it is highly likely that there are microplastics in the seafood we buy from super markets or get at restaurants.
There are still a lot of question to be answered.
- Are there microplastics in other marine animal soft tissues (i.e. do the fish we eat also have microplastics in their tissues?)
- When we eat these tissues, are the plastics passing into our bodies, or being excreted?
- What are the toxicological or physiology threats of having microplastics in our bodies?
- Microplastics threaten Oysters in British Columbia (here)
- Microplastics in bivalves cultured for human consumption research publication (here)
- or read the Telegraph article (here)